Nearly one million Americans are HIV-positive, but about half of them are either not aware they are infected with HIV or are not seeking care for the disease, the New York Times reports. The statistics were part of a number of reports issued yesterday at the Conference on Retroviruses and Opportunistic Infections in Seattle.

One report by CDC researcher Dr. Patricia Fleming and colleagues stated that an estimated 850,000 to 950,000 Americans are infected with HIV, but 180,000 to 280,000 of this population is unaware that they are HIV-positive (Altman, New York Times, 2/26). The proportion of HIV-positive people who do not know that they carry the virus has declined in recent years, dropping from approximately 33% in 1998 (Maugh, Los Angeles Times, 2/26).

In addition, one-third of those who know they are HIV-positive are not receiving treatment. Dr. Harold Jaffe, acting director of the CDC's National Center for HIV, STD and TB Prevention, said that there are several reasons that many HIV-positive individuals are not seeking care.

He stated that many younger people did not witness "the [AIDS] epidemic in full force" 15 years ago and "falsely" believe that current treatment can cure HIV. In addition, some younger people at risk for HIV infection have "grown tired of hearing warnings about AIDS" and advertisements for antiretroviral drugs "create misleading impressions" by depicting "supposedly infected" individuals who appear "perfectly healthy," Jaffe said (New York Times, 2/26).

Dr. Constance Benson of the University of Colorado Health Sciences Center said that some people are being "dissuaded" from getting tested for HIV because they hear reports of the adverse effects of antiretroviral drugs. Jaffe said that the CDC is launching a new public education drive to encourage people to get tested for HIV (Los Angeles Times, 2/26).

AIDS Deaths Down, HIV Infections Still Rising

Although the number of HIV infections in the United States continues to rise, the advent of better antiretroviral treatment has led to a decline in AIDS-related deaths, meaning that the overall prevalence of HIV in the U.S. population is increasing, the Milwaukee Journal Sentinel reports.

New HIV infections have risen steadily at a rate of approximately 40,000 infections per year, but AIDS-related deaths have dropped by more than 50% since 1996, when the use of combination therapy including protease inhibitors became more widespread.

Fleming said that the number of people living with HIV is "outpacing" the number of people dying from AIDS-related causes by 25,000 per year. At this rate, the prevalence of HIV infection in the U.S. population is growing nearly 3% per year (Marchione, Milwaukee Journal Sentinel, 2/26). If this trend continues, the total number of HIV-positive people in the United States will reach one million "in the next year or two," Fleming stated (Sternberg, USA Today, 2/26). An abstract of Fleming's study can be viewed online.

HIV-Positive Patients Need Treatment Earlier

Another study presented at the conference found that 40% of HIV-positive Americans begin antiretroviral treatment later than is recommended in federal HIV treatment guidelines. Federal guidelines stipulate that antiretroviral treatment should generally begin when the a patient's CD4+ T cell count falls below 350, and treatment should "definitely" begin when the T cell count drops to 200 or below.

CDC researcher Dr. A.D. McNaghten and colleagues studied 10 U.S. cities and found that 40% of HIV-positive people do not begin therapy until after the recommended time period. Jaffe said that many AIDS-related deaths are occurring among people who do not seek care until their disease has reached an advanced stage, noting that 5% of all AIDS cases are diagnosed within a month of a patient's death.

The CDC is urging broader use of a rapid HIV test that can produce results the same day so that people do not have to wait a week or longer for the results. The agency is also urging hospitals to make HIV testing "more of a routine part of health care" (New York Times, 2/26). An abstract of McNaghten's study can be viewed online.

People With AIDS Dying More From Other Causes

CDC officials presented another report indicating that fewer people with AIDS are dying from diseases commonly associated with AIDS, such as tuberculosis and pneumonia, and are increasingly dying from other conditions such as liver and kidney disease. CDC researcher Dr. Mitchell Wolfe and colleagues analyzed deaths among people with AIDS that occurred before 1996 and after 1996.

The study found that before 1996, TB accounted for 4.4% of AIDS-related deaths, compared to 1.9% of such deaths after 1996. The proportion of AIDS patients who died from pneumocystis pneumonia fell from 10.6% before 1996 to 6.7% after 1996. However, the proportion of AIDS patients who died from kidney disease rose from 8% before 1996 to 10.3% after 1996, while the proportion of AIDS patients who died from liver disease rose from 5.4% before 1996 to 8.1% after 1996.

Wolfe said that there are several reasons for this trend, including the fact that some antiretroviral drugs cause liver and kidney damage. But he added that antiretroviral treatment has extended the lifespan of many people with HIV and that kidney and liver diseases are more common in older people.

In addition, the drop in TB- and pneumonia-related deaths could be attributed to better treatments for these infections and the stronger immune systems of HIV-positive patients taking antiretroviral drugs (Los Angeles Times, 2/26).